Journal club: Specialist phenomena stems from differential concentrations

Journal article for 09/13/2013:
An amino acid substitiution inhibits specialist herbivore production of an antagonist effector and recovers insect-induced plant defenses by Schmelz et al. (2012)

Overall, the research presented seems reasonably executed as well as interpreted.

It's a misnomer to call  [Vu-In$^{-A}$] "inactive" when it has antagonistic repressive functionality.

The dynamics of plant reaction due to different ratio of inceptin concentration produced by FAW and VBC reminded me of a somewhat recent news article, Plants perform molecular maths. While not as complex as the rate of starch degradation discussed in the news article as these inceptin classes might just be competing for receptor real-estate, the data suggest that their might be something more complex occuring.

After finding that VBG repressed plant reaction to predation by itself through production of more  [Vu-In $^{-A}$] than [Vu-In], they performed a titration of the two compounds to gauge plant reaction dependent on different ratios.

Figure 3B shows the results of different concentrations. I found it interesting that when [Vu-In $^{-A}$] : [Vu-In] were 1:1, the ET production was the same as when the entire treatment was [Vu-In].  More interestingly, the pseudo dose-response of each of inceptins can be seen in Figure 3A which can describe the paired dose response.

So, since this specialist phenomena seems to be the result of different concentrations of inceptins. It would have been nice to see the paired dose response for Vu-In $^{-A}$ and Vu-In $^{\bigtriangleup V}$ to see if the defense response is considerably antagonized by the ~77% Vu-In $^{-A}$ as it was in Fig 3B.

TL;DR (comment):
With respect to Figure 3B, I found it interesting that in the paired-dose response when the two inceptins were 1:1, the ET production was similar as when the entire treatment was [Vu-In].  I agree with the authors, that, based on their data, it looks like this specialist phenomena stems from differential concentrations of inceptins in the OS. I think it would have been nice to see the paired dose response for Vu-In $^{-A}$ and Vu-In $^{change V}$ to see if the defense response is again considerably antagonized by the ~77% Vu-In $^{-A}$ as it was in Fig 3B.

Comments